Biology 2.2 - Control and Communication

• What is the nervous system comprised of?

  • The central nervous system (CNS)
  • The peripheral nervous system (PNS)
• What are the two parts of the Central Nervous System?

  • The brain
  • The spinal cord
• What is peripheral nervous system?

  The nerves
• What are the three parts of the brain?

  • Cerebrum
  • Cerebellum
  • Medulla
• What does the cerebrum look like?

  A

  
• What is the function of the cerebrum?

  • Conscious thought
  • Intelligence
  • Language
• What does the cerebellum look like?

  B

  
• What is the function of the cerebellum?

  • Balance
  • Coordination
• What does the medulla look like?

  C

  
• What is the function of the medulla?

  • Unconscious control
  • Body temp
  • Heart rate
  • Breathing rate
• Define neuron?

  Specialised cells which carry electrical messages (impulses) around the body
• What are the three types of neurons?

  Acronym = SIM

  • Sensory
  • Inter
  • Motor
• Sensory Neurons?

  Impulse travels from receptors to inter neurons

  Are found in the PNS (Peripheral nervous system)
• Inter Neurons?

  Impulse travels from sensory neuron to motor neuron

  Are found in the CNS (Central Nervous System)
• Motor Neurons?

  Impulse travels from inter neuron to a muscle or gland

  Are found in the PNS (Peripheral Nervous System)
• What do receptors do?

  Detect stimuli / sensory information
• What do electrical impulses do?

  Carry messages along neurons
• What does a synapse do?

  Transfer messages between neurons by chemical messengers
• What are reflex actions?

  Involuntary protective movements
• The reflex arc pathway is?

  Receptor -> Sensory Neuron -> Inter Neuron -> Motor Neuron -> Response

  OR

  Receptor -> SIM -> Response
• What is the junction where two neurons meet called?

  Synapse
• Do synapses touch?

  Synapses do not touch
• Can the electrical message cross the gap?

  The electrical message cannot cross the gap
• What transfers the message across the gap?

  • Chemical messengers
  • Neurotransmitters
• Synapse Process?

  1. Electrical impulse arrives at a synapse
  2. Chemical messengers or neurotransmitters carry the signal across the synapse by diffusion
  3. A new electrical impulse is generated in the next neuron
• What are the two categories of glands?

  • Endocrine glands
  • Exocrine glands
• What do endocrine glands do?

  Secrete hormones into the bloodstream
• Do endocrine glands have ducts?

  Endocrine glands do not have ducts
• What are hormones?

  Proteins that act as chemical messengers
• The target cell is the cell that is due to receive the chemical
• The secreting cell is a cell in the gland
• The receptor is a part of the cell that allows for the attachment of the hormone to the target cell
• How does a hormone work?

  
  

  1. The secreting cell in the gland produces a hormone
  2. The hormone travels down a blood vessel to join with a receptor in the target cell
• When is insulin released?

  Insulin is released when the blood sugar rises above normal
• What does insulin cause?

  Insulin causes liver and muscle cells to remove glucose from the blood
• When is glucagon released?

  Glucagon is released when the blood sugar falls lower than normal
• What does glucagon cause?

  Glucagon causes liver and muscle cells to release glucose into the blood
• What does the pancreas do?

  The pancreas is the endocrine gland which produces insulin and glucagon